Limited Optimal Plastic Behavior of RC Beams Strengthened by Carbon Fiber Polymers Using Reliability-Based Design

Abstract

The plastic behavior of strengthened haunched beams utilizing carbon fiber-reinforced polymers (CFRP) was investigated using a probabilistic design that took into account random concrete properties, CFRP properties, and complementary strain energy values, with the reliability index serving as a limiting index, as the proposed method considers a novel method that deals with probabilistic parameters for models with limited plastic behavior designed based on the reliability index. The data used in this research were gathered and evaluated in a recent study on simply supported haunched beams reinforced with carbon fiber-reinforced polymers. The purpose of this research was to use the reliability limitation index for simulated strengthened haunched beams by taking into account randomness in concrete and CFRP properties and the complementary strain energy value, which is considered a plastic behavior controller that provides an illustration of the damage amount within the reinforcement steel bars. The results indicate how randomness affects the behavior of the presented models, which are chosen to have different numbers of CFRP strips. The variable randomness affects load and deflection values where the reliability index value increases as the corresponding load value decrease, reflecting the increased probability of failure in models subjected to higher loading conditions, while tension concrete damage percentages are reflected in the damage pattern presented in the results, showing that as the produced load increases, so does the damage intensity. It is also obvious that the reliability index served as a limitation index while taking concrete characteristics and complementary strain energy as random variables.

Elasto-Plastic Analysis of Two-Way Reinforced Concrete Slabs Strengthened with Carbon Fiber Reinforced Polymer Laminates

“…This discovery might have important implications for the design and construction of reinforced concrete structures, especially in areas prone to earthquakes where ductility is a critical factor [19]. Various combinations of damage and plasticity were explored by Carol et al [20] in 2001, Ibrahim et al [21] in 2023, and Rad et al [22] in 2023. Gatuingt and Pijaudier-Cabot [23], in 2002, and Kratzig and Polling [24], in 2004, utilized isotropic damage in their research, elucidating various combinations of plasticity types.…”

Analysis and prediction of compressive and split-tensile strength of secondary steel fiber reinforced concrete based on RBF fuzzy neural network model

“…Chen’s experiments [ 25 ] aligned with Zhao’s filitting tensile strength depending on the concrete grade; for C30 steel fiber-reinforced concrete, an increase in fiber length led to reduced strength, whereas for C60 concrete, strength increased with longer fibers. Khaleel Ibrahim & Movahedi Rad [ 26 ] studied the plastic properties of beams reinforced by carbon fiber reinforced polymer (CFRP) by using probabilistic design method which takes into account random concrete properties, carbon fiber reinforced polymer (CFRP) properties and complementary strain energy values.The study on the optimal plastic behavior of RC beams strengthened by carbon fiber polymers offers valuable insights into reliability-based design approaches. Despite these studies, there is a dearth of consistent data specifically on the compressive and splitting tensile strengths of secondary steel fiber reinforced concrete.…”

Experimental and Numerical Study on RC Beams Strengthened by NSM Using CFRP Reinforcements

“…Movahedi Rad et al [25] introduced an innovative numerical optimization to control the plastic behavior of reinforced concrete haunched beams. Khaleel Ibrahim and Movahedi Rad [26,27] applied an optimal reliability-based design approach to reinforce concrete haunched beams and CFRP-strengthened beams. Taking into account the probabilistic nature of concrete properties and complementary strain energy values.…”